Lightning-arrester.



No. 724,339. PATENTED MAR. 31, 1'903.

M. SHAW. y

LIGHTNING ARRBSTBR.

APPLICATION FILED SEPI 20 1901 N0 MODEL.

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:UNITED STATES PATENT FFICE.

HARRY M. SI'IAVV, OF NEWARK, NEW JERSEY.

LIGHTNINGTQARRESTER.

sPnoIFlcAfrtoN forming part of Letsratent No. 724,339, dated March 31, 1903. vApplication filedSeptember 20,-,1901I Serial No. 75.886. (No model.)

T0 all whom, it may concern,.-

Bc it known that I, HARRY M. SHAW,- a citizen of the United States, and a resident ofl Newark, in the county of Essex and State ofk New Jersey, have invented certain new and useful Improvements in Lightning-Arresters, of which the following is a specification.

My present invention relates to lightning-i arresters for application to circuits which l would form arcs or which are of sufficient pojtential to cause a continuance of a discharge of current when the spaces of the lightningarrester have been bridged by a discharge ind uctively produced by the clouds. j

My presentinvention relates toan improved means for protecting electrical apparatus from damage by lightning or atmospheric dis-Y charges of electricity, which discharges, although they may not in themselves be sufficient to materially injure the apparatus, often provide a path for the current generated by the apparatus or flowing therethrough,which then is liable to cause damage to the apparatus. Y

The object of my invention is to provide a lightning-arrester having features of novelty and advantage, and in the drawings I have shown one embodiment of my invention.

Figure l is a prospective view with parts of the casing broken away. Fig. 2 is a perspec tive View ofthe arrester removed from its.

casing.

A is the casing in which the lightningfarrester is located and has on its frontsidea removable cover B.

C is a plate of insulating material, such asY slate, to which the parts of my lightning-ar-- rester are secured. To thisplate are secured' ribbons of metal D D', preferably of brass, by means of the screws d d', which also constitute binding-posts for the attachment of the stranded wire d2 and the ground-wire d3. These ribbons of metal D D project upwardly from the slate piece C. Then their ends are bent toward each other substantially parallel with the base, asis clearly shown in the drawings at e e, their opposing edges being serrated or toothed.

E denotes a composite body made up of plates of non-arcing material F, such as carbon and thin sheets of mica G,arran ged in alternation. These plates of carbon are mounted on the l verted into the flat disks of carbon.

l; insulating-washers I and the plates of mica extend down between these insulating-washers to the bolt L, which is of a non-conducting material, such as liber. The ends of the bolt pass through the upright parts of the rib bons D D and are secured thereto by means 1' of nuts, so'that the composite body E just abouty lls the space between the serrated ends ee of the ribbons D D.

The current is fed to the instrument first through the stranded Wire until it reaches the Hat ribbon D, Where it spreads throughout this flat ribbon and is broken into small dischargesV from the serrated ende and di- Here it is broken up into infinitesimal sparksin passing from one carbon diskover or through the insulator to the succeeding carbon disk,`and so on until it is received at the serrated ends e of the ribbon D', from whence it is led off into the ground through the wire d3.

It has been common in lightning-arresters to provide two metal plates having oppositely-disposed serrated portions, but without any intervening substance between the serrated portions. It has been found by the Vuse -of an instrument of this kind that the air is apt to become highly heated and arcs formed, andsuch a construction has never been fully satisfactory. It has also been customary to provide in a lightning-arrester a series of alternately-arranged plates of non-arcing metal and mica or plates of non-arcing material insulated from one another and separated by an air-space; but good results have never been obtained from such a construction. I have found that the best result can be obtained by providing a composite body of carbon and mica or carbon and air-gaps arranged in alternation and delivering the current to the carbon through a flat ribbon of metal having a serrated end and in taking the current from the opposite end of this composite body through a hat ribbon of metal having a serrated end and from there to the ground, and, further, in mounting these alternate layers of carbon and mica on an insulating-sleeve of fiber, the whole being supported by a bolt of fiber secured to the flat ribbon of metal. Thus this composite body is completely insulated, and the current delivered to it at one end must pass over or ICO through the successive mica steps or air-gaps and the carbon.

I claim as my inventionl. In a lightning-arrester, in combination the insulating-base, the metal ribbons havingoppositely-disposed serrated ends,and the composite body made up of alternate plates of a non-arcing material and mica, said com supported thereon and having oppositely-disposed serrated edges, a composite body made up of alternate plates of carbon and mica arranged on a non-conducting sleeve, said body being positioned between the serrated ends of said metallic ribbons, and a bolt of nonconducting material passing through said sleeve and having its ends secured to said metallic ribbons, ysubstantially as described.

4. n a lightning-arrester, in combination, the insulating-base, the metallic ribbons having oppositely-disposed serrated ends, and a composite body made up of a series of plates of non-arcing material insulated from one another and separated by a non-conductor, said composite body being insulated from its support and positioned between the serrated ends of the metallic ribbons, substantially as described.

HARRY M. SHAW.

Witnesses:

Il. C. WILLIs', O. T. HUNGERFORD. 

